Apparatus for making iron oxides



T. FRENCH. APPARATUS FOR MAKINGIRON OXIDES.

APPLICATION FILED MAY 4, 1921.

Patented Dec. 12, 1922.

INVENTUR Patented Dec. 12, 1922, I

UNITED. STATE FRENCH, arm-.0 one APPARATUS ron MAKING mom bis-Iss,

Ap lication filed May 4, 1921. Serial m.f46e as9 I To all whom it may concern:

Be it known that I, THOMAS FRENCH, of J the city of Guelph, in the county of Well-' ington, Province of Ontario, Canada, a Sub ject of the King of Great Britain, have invented certain new and useful Improvements in Apparatus for Making Iron Oxides, of which the following a specifi cation.

This invention relates to means for producing iron oxides by subjecting ironsalts, such as the sulphate, to an oxidizing roast.

With existing apparatus for this purpose the difficulty is to satisfactorily control the temperature and the amount of air admitted to re-act with the charge, and, when iron oxides are to be used as pigments, perfect control is essential to enable the exact shade of color desired in the finished product to be obtained. This is particularly the case when the lighter shades of color are to be produced. 7

My object therefore is to devise a furnace which will enable an operator to perfectly control both temperature and air admission and in which the means provided for-admitting air are also best adapted to enable the progress of the reaction to be easily watched by the operator.

I attainmy object by means of the construction hereinafter described and illustrated in the accompanying drawings in which- Fig. 1 is a front elevation of my improved furnace;

Fig. 2 a longitudinal section;

Fig. 3 a transverse section on the line 6-?) in Fig. 2; and

Fig. 4 a horizontal section on the line cc in Fig. 2.

In the drawings like numerals of reference indicate corresponding parts in the different figures.

The furnace is constructed as usual of brickwork and will be provided with the usual refractory linings wherever necessary. At one side of the furnace is located the fire place 1 provided with. the usual doors and separated from the chamber 2 of the furnace by a fire bridge 3. The furnace chamber is comparatively lofty and is provided with an arched roof as shown. At the opposite side of the chamber to the fire place is located a flue 4 communicating with the interior of the chamber intermediate the top and bottom of the chamber. This "serves to "bustion passingiupthejchimney through a flue communicates aaaehiilint I5. The

topof the chimney-"is, preferably provided with a bin ed damper-,6, which, when closed, irec'tf'gases and products of comp'ipef7 to a-suitablegcondenser' (not shown.) in which condensa-b "products-are recovered. v 4 v l i In the chimney 5,,"is IOca'teda 'afSIiding damper 8 by ,means ofwhich the'furnace chamber may be entirely out off from communication with the chimney and the pipe 7 when desired.

In the front of the furnace are located the working doors 9, the arrangement and proportioning of which forms an important part of the construction. will be noted, serve to close an opening, the lower end of which is about at the level of the floor of the chamber 2, and which opening is only about half the height of the chamber 2. The doors are double and are hinged at 10 bytheir outer edges on the outer wall of the furnace. From this arrangement it follows that if the doors are partly bpened, triangular spaces are left at the top and bottom of the doors and a vertical rectangular space between- These doors, it

end of this flue is provided with a damper 14 by means of which it may be closed as desired, while from the flue leads a pipe 15 ,through which acid fumes may be led away to a condenser such as hereinbefore referred to. p

The mode of operation of the furnace -is substantially .as follows. When a previous charge has been finished and withdrawn from the furnace, the temperature in the furnace chamber has become somewhat lowered. The doors 9 and 11 are then closed and the dampers 6 and 8 opened. The fire in the fire place is made up and urged as much as may be necessary. The interior of the furnace soon attains a bright red heat.

and a charge of the iron compound, usually ferrous sulphete, is introduced and spread out on the bed of the furnace chamber. e doors 9 are either kept closed altogether at this stage or they are only slightly opened. As soon as the charge becomes ciently heated to give off its acid gas, the damper 8 is patrinlly or wholly closed, depending on the co perature, end the doors 9 are opened a few inches. The opening of the door leaves a. 1'1" space at the top and bottom as already described and through the lower-spuce e current of air w enter the furnace in such or way that it forms m :e v; layer of air to a depth of a few inches above the surface of the charge and exten' over every part of the bed of the furna. en the damper 8 is clomd, all the smoke and the acid fumes from the decomposing sulphate emerge fiom the mall tri i. l r opening at the top of the partially opened doors 9.

wit the upper part of the furnace cold air and to allow amore repid escape of the heated gases in the upper part of the chamber. When the decomposition and oxidation of the charge becomes largely completed, the temperature tends to become too low for the proper finishingof the operation. In this case the doors 9 will require to be further closed to prevent the entrance of too much air and the escape of too great a quantity of the products of combustion, while the damper 18 may require to be more or less opened in order to increase the draft of the fire.

The charge in the furnace is turned over frequently in order to expose new surfaces to the air. As soon as oxidation is complete, the charge is withdrawn from the furnace through the doors 9 and 11. The products of "combustion and acid gases emerging at the top of the doors 9 are collected by the hood and carried to the condenser as already described, as are also any gases passing through the flue 45 to the chimney 5. lf for any reason the condenser should be out of action, the products of combustion pass through the top of the essrs The rectangular opi All jacent edges of the doors 9, when the latter are portly open, gives an operator o perfect.

view of the interior of the ace so that the condition of the cherge at any moment is readily observed.

It will be understood that while this furuses is particularly edaptcd for the produc tron of iron oxides from salts of iron, it mey be used for roasting and calc r w other ores.

lt will be understood that eitr solid, liq;

bid or gaseous fuels may be used in the fire place according to circumstances. What I claim as my invention is:-

vided with a chamber; a fire place at one side of the chamber; a fire bridge separating the chamber fi'om the fire place; a flue leadmg from the side of the furnace chamber opposite the fire place and intermediate the top and bottom of the chamber; at damper in said flue; an opening in the fi-ont well of the furnace materially less in height than the chamber and having its lower side substantially at the level of the chamber floor; a pair of doors vertically hinged by their outer edges at opposite sides of said ope ing; said doors being adapted to meet and.

closersaid opening when required or to open and leave openings above and below as well' as between their adjacent edges when more or less opened; and an external gas collect-.

ing hood overthe opening and its doors.

2. A furnace of the type described providedwith a chamber; a fire place at one side of the chamber; a fire bridge separating the chamber from the fire place; a. flue leading from the side of the furnace chamber opposite the fire place and intermediate the top and bottom of the chamber; a damper in said flue; an opening in the front wall of the furnace materially less in height than the chamber and having its lower side substantially at the level of the chamber floor; a pair of doors vcrtically' hinged by their outer edges at opposite sides of sald opening; said doors being adapted to meet and close said opening when re- Ill 1. A ace of the type described proquired or to open and leave openings above and below as well as between their adjacent edges when more or less opened, and one or more small door-closed openings in the fur nace wall adjacent the main opening; and an external gas collecting hood over the openings and doors.

- Signed at Toronto, Can, this 29th day of April, 1921. v

THOMAS FRENSH. 

